Structure of Diatom Community in a Hydropower Impacted Himalayan River
DOI:
https://doi.org/10.55863/ijees.2026.0996Keywords:
Hydropower, Glacier-fed river, Alaknanda river, Biomontoring, HydropeakingAbstract
Hydropower development significantly alters the natural flow regime, affecting the riverine biodiversity of mountain
rivers. This study assesses the impacts of hydropower on the diatom community structure in the dewatered stretch
downstream of the dam at Srikot and the regulated stretch below the powerhouse in the Alaknanda River. Sampling
was conducted monthly to examine the temporal variation in the diatom community and its environmental drivers.
The diatom community structure revealed a marked difference between the two sites. At Srikot, the persistent
dominance of the tolerant taxon Achnanthidium latecephalum, along with recurring nutrient-tolerant taxa, indicates
community homogenization under reduced discharge and nutrient accumulation. In contrast, a shift among
dominants A. minutissimum, A. latecephalum, Cymbella excisa, Gomphonema olivaceum, and A. pyrenaicum at
Srinagar reflects habitat instability due to hydropeaking requirements. Canonical correspondence analysis identifies
water temperature and electrical conductivity as major drivers of the community in the dewatered section at Srikot. In
contrast, water current velocity and transparency are the major drivers in the regulated section at Srinagar. The study
revealed that flow regulation for hydropower alters the diatom community structure associated with low discharge
and hydropeaking requirements. These findings highlight the sensitivity of diatoms as indicators of hydrological
disturbances and emphasise the need for further region-specific biomonitoring strategies and flow management in
Himalayan regulated rivers, particularly those with glaciers at their sources.
References
Anonymous, 1982. Etude des methodes biologiques d'appreciation quantitative de la qualite des eaux. Division Quality des Eaux, Agence de Bassin Rhone-Mediteranee-Corse, CEMAGREF, Lyon, France. 218 pages.
Branche, E. 2017. The multipurpose water uses of hydropower reservoirs: The share concept. Comptes Rendus Physique, 18(7-8), 469-478. https://doi.org/10.1016/j.crhy.2017.06.001
Bartwal, T. and Nautiyal, P. 2023 a. Hydropower development in the Himalaya: Identifying critical river stretches. Environmental Science and Pollution Research, 30(16), 46741-46747. https://doi.org/10.1007/s11356-023-25401-1
Bartwal, T. and Nautiyal, P. 2023 b. Diatom communities in the Himalayan River (lower stretch of Alaknanda, Srinagar): Periodic variations in relative abundance. Indian Journal of Ecology, 50(3), 819-825. https://doi.org/10.55362/IJE/2023/
Bartwal, T. and Nautiyal, P. 2025. Decadal variation in the diatom community structure of a Himalayan river. Environmental Monitoring and Assessment, 197(7), 738. https://doi.org/10.1007/s10661-025-14162-8
Bipa, N.J., Stradiotti, G., Righetti, M. and Pisaturo, G.R. 2024. Impacts of hydropeaking: a systematic review. Science of the Total Environment, 912, 169251. https://doi.org/10.1016/j.scitotenv.2023.169251
Bere, T. and Tundisi, J.G. 2011. Influence of land-use patterns on benthic diatom communities and water quality in the tropical Monjolinho hydrological basin, São Carlos-SP, Brazil. Water SA, 37(1), 93-102. https://scielo.org.za/scielo.php?script=sci_arttext&pid=S1816-79502011000100012
Buczkó, K., Trábert, Z., Stenger-Kovács, C., Tapolczai, K., Bíró, T., Duleba, M., Földi, A., Korponai, J., Vadkerti, E., Végvári, Z. and Ács, É. 2022. Rapid expansion of an aquatic invasive species (AIS) in Central-European surface waters: A case study of Achnanthidium delmontii. Ecological Indicators, 135, 108547. https://doi.org/10.1016/j.ecolind.2022.108547
Chen, Q., Zhang, X., Chen, Y., Li, Q., Qiu, L. and Liu, M. 2015. Downstream effects of a hydropeaking dam on ecohydrological conditions at sub-daily to monthly time scales. Ecological Engineering, 77, 40-50. https://doi.org/10.1016/j.ecoleng .2014 .12.017
Chong, X.Y., Vericat, D., Batalla, R.J., Teo, F.Y., Lee, K.S.P. and Gibbins, C.N. 2021. A review of the impacts of dams on the hydromorphology of tropical rivers. Science of the Total Environment, 794, 148686. https://doi.org/10.1016/j.scitotenv.2021.148686
Coste, M. Boutry, S., Tison-Rosebery, J. and Delmas, F. 2009. Improvements of the Biological Diatom Index (BDI): Description and efficiency of the new version (BDI-2006). Ecological Indicator, 9(4), 621-650. https://doi.org/10.1016/j.ecoli nd.2008.06.003
Dell’Uomo, A. 1996. Assessment of water quality of an Apennine river as a pilot study for diatom based monitoring of Italian watercourses. pp. 65-72. In: Whitton, B.A. and Rott, E. (Eds.), Use of Algae for Monitoring Rivers II. Institut für Botanik, Universität Innsbruck, Innsbruck.
Descy, J.P. and Coste, M. 1991. A test of methods for assessing water quality based on diatoms. Verhandlungen der Internationalen Vereinigung für theoretische und angewandte Limnologie, 24, 2112-2116. https://doi.org/10.1080/03680770.1989.11899905
Dudgeon, D., Arthington, A.H., Gessner, M.O., Kawabata, Z.I., Knowler, D.J., Lévêque, C., Naiman, R.J., Prieur-Richard, A.H., Soto, D., Stiassny, M.L. and Sullivan, C.A. 2006. Freshwater biodiversity: importance, threats, status and conservation challenges. Biological Reviews, 81(2), 163-182. https://doi.org/10.1017/S1464793105006950
Falasco, E., Piano, E. and Bona, F. 2016. Diatom flora in Mediterranean streams: Flow intermittency threatens endangered species. Biodiversity and Conservation, 25, 2965-2986. https://doi.org/10.1007/s10531-016-1213-8
Goldenberg‐Vilar, A., Delgado, C., Penas, F.J. and Barquín, J. 2022. The effect of altered flow regimes on aquatic primary producer communities: Diatoms and macrophytes. Ecohydrology, 15(1), e2353. https://doi.org/10.1002/eco.2353
He, F., Zarfl, C., Tockner, K., Olden, J.D., Campos, Z., Muniz, F., Svenning, J.C. and Jähnig, S.C. 2024. Hydropower impacts on riverine biodiversity. Nature Reviews Earth & Environment, 5(11), 755-772. https://doi.org/10.1038/s43017-024-00596-0
Jakovljević, O., Krizmanić, J., Vasiljević, B. and Popović, S. 2024. The response of the diatom community to small hydropower plant and fish farm. International Journal of Limnology, 60, 4. https://doi.org/10.1051/limn/2024004
Jüttner, I. and Cox, E. J. 2001. Diatom communities in streams from the Kumaon Himalaya North-West India. pp. 237-248, In: Economou-Amilli, A. (Ed.), Proceedings of 16th International Diatom Symposium, Amvrosiou Press, Athens, Greece.
Kelly, M.G. and Whitton, B.A. 1995. The trophic diatom index: a new index for monitoring eutrophication in rivers. Journal of Applied Phycology, 7(4), 433-444. https://doi.org/10.1007/BF00003802
Kelly, M., Juggins, S., Guthrie, R., Pritchard, S., Jamieson, J., Rippey, B., Hirst, H and Yallop, M. 2008. Assessment of ecological status in UK rivers using diatoms. Freshwater Biology, 53(2), 403-422. https://doi.org/10.1111/j.1365-2427.2007.01903.x
Krammer, K. 2002. Cymbella. Pp. 152-179. In: Lange-Bertalot, H. (Ed.), Diatoms of Europe, Diatoms of the European Inland Waters and Comparable Habitats. Vol. 3, A.R.G. Gantner Verlag K.G., Rugell, Koeltz Scientific Books, Koenigstein, Germany.
Krammer, K. 2003. Cymbopleura, Delicata, Navicymbula, Gomphocymbellopsis, Afrocymbella. In: Lange-Bertalot, H. (Ed.), Diatoms of Europe, Diatoms of the European Inland Waters and Comparable Habitats Vol 4, A.R.G. Gantner Verlag K.G., Rugell, Koeltz Scientific Books, Koenigstein, 530 pages.
Krammer, K. and Lange-Bertalot, H. 1986-2000. Bacillariophyceae. Die Susswasser flora von Mitteleuropa. Vol. 2/1 Naviculaceae, pp. 1-876, 206 pl. (1986). Vol. 2/2 Bacillariaceae, Epithemiaceae, Surirellaceae, pp. 1-596 (1988). Vol 2/3 Centrales, Fragilariaceae, Eunotiaceae, pp. 1-576 (1991a). Vol. 2/4 Achnanthaceae, Navicula sensu stricto and Gomphonema. pp. 1-43 (1991b). Vol. 2/5 English and French translations of the keys (2000). Stuttgart and Heidelberg, Berlin.
Kumar, S. and Nautiyal, P. 2024. Assessment of ecological state of serially impounded Himalayan River using diatom-based matrices: Identification of critical stretches for management. Ecological Frontiers, 44(2), 321-326. https://doi.org/10.1016/j.chnaes.2023.07.009
Leclercq, L. and Lecointe, C. 2008. Présentation de l'indice diatomique de saprobie-eutrophisation (IDSE) introduit dans la nouvelle version de Omnidia. 27ème Colloque de l'ADLaF Dijon, Livre des résumés. F. R. a.
Lange-Bertalot, H. 2001. Navicula sensu stricto. 10 genera separated from Navicula sensu lato. Frustulia. In: Lange-Bertalot, H. (Ed.) Diatoms of Europe, Diatoms of the European Inland Waters and Comparable Habitats Vol. 2, A.R.G. Gantner Verlag K.G., Ruggell, Koeltz Scientific Books, Koenigstein. 526 pages.
Lange-Bertalot, H., Cavacini, P., Tagliaventi, N. and Alfinito, S. 2003. Diatoms of Sardina. Biogeography-Ecology-Taxonomy, Iconographia Diatomol, vol. 12, A.R.G. Gantner & K.G. Verlag, Ruggell. 438 Pages.
Lee, K.L., Choi, J.S., Lee, J.H., Jung, K.Y. and Kim, H. S. 2021. Response of epilithic diatom assemblages to weir construction on the Nakdong River, Republic of Korea. Ecological Indicators, 126, 107711. https://doi.org/10.1016/j.ecolind.2021.107711
Mbao, E.O., Odinga, E.S., Nyika, J., Ochieng, B. and Kitaka, N. 2022. A bibliometric study on the use of diatoms in water quality monitoring and bioassessment in Africa across 10-year (2012–2022) period. Aquatic Sciences, 84(4), 58. https://doi.org/10.1007/s00027-022-00891-2
Metzeltin, D. and Lange-Bertalot, H. 2002. Diatoms from the island continent of Madagascar. Annotated Diatom Micrographs. In: Lange-Bertalot H. (Ed.) Iconographia Diatomologica Vol. 11, A. R. G. Gantner Verlag K.G., Ruggell. 286 pages.
Metzeltin, D., Lange-Bertalot, H. and Garcia-Rodriguez, F. 2005. Diatoms of Uruguay. Taxonomy-Biogeography – Diversity. Annotated Diatom Micrographs, Vol. 15, Pp. 726, 240 plates. In: Lange-Bertalot, H. (Ed.) Iconographia Diatomologica, A.R.G. Gantner Verlag K. G., Ruggell.
Norkko, A., Rosenberg, R., Thrush, S.F. and Whitlatch, R.B. 2006. Scale- and intensity-dependent disturbance determines the magnitude of opportunistic response. Journal of Experimental Marine Biology and Ecology, 330(1), 195-207. https://doi.org/10.1016/j.jembe.2005.12.027
Pérès, F., Barthès, A., Ponton, E., Costes, M., Ten-Hage, L. and Le-Cohu, R. 2012. Achnanthidium delmontii sp. nov., a new species from French rivers. Fottea, 12(2), 189-198. https://doi.org/10.5507/fot.2012.014
Peterson, C.G. and Stevenson, R.J. 1992. Resistance and resilience of lotic algal communities: Importance of disturbance timing and current. Ecology, 73(4), 1445-1461. https://doi.org/10.2307/1940689
Potapova, M. and Charles, D. F. 2003. Distribution of benthic diatoms in U.S. rivers in relation to conductivity and ionic composition. Freshwater Biology, 48(8), 1311-1328. https://doi.org/10.1046/j.1365-2427.2003.01080.x
Potapova, M. and Hamilton, P. B. 2007. Morphological and ecological variation within the Achnanthidium minutissimum (Bacillariophyceae) species complex. Journal of Phycology, 43(3), 561-575. https://doi.org/10.1111/j.1529-8817.2007.00332.x
Poff, N.L., Olden, J.D., Merritt, D.M. and Pepin, D.M. 2007. Homogenization of regional river dynamics by dams and global biodiversity implications. Proceedings of the National Academy of Sciences United States of America, 104(14), 5732-5737. https://doi.org/10.1073/pnas.0609812104
Rott, E., Hofmann, G., Pall, K., Pfister, P. and Pipp, E. 1997. Indikationslisten für Aufwuchsalgen. Teil 1: Saprobielle Indikation. Bundesministerium für Land- und Forstwirtschaft, Vienna. pp. 73.
Rott, E., Pipp, E., Pfister, P., van Dam, H., Orther, K., Binder, N. and Pall, K. 1999. Indikationslisten für Aufwuchsalgen in Österreichischen Fliessgewassern. Teil 2: Trophieindikation. Bundesministerium für Land- und Forstwirtschaft, Vienna, Austria. 248 pages.
Rumeau, A. and Coste, M. 1988. Initiation à la systématique des diatomées d'eau douce. Pour l'utilisation pratique d'un indice diatomique générique. Bulletin Français de la Pêche et de la Pisciculture, 309, 69. https://doi.org/10.1051/kmae:1988009
Schultz, K., Dreßler, M., Karsten, U., Mutinova, P.T. and Prelle, L.R. 2024. Benthic diatom community response to the sudden rewetting of a coastal peatland. Science of the Total Environment, 955, 177053. https://doi.org/10.1016/j.scitotenv.2024.177053
Sharma, S. and Nautiyal, R. 2022. Diatom assemblages in the natural, impounded and regulated sections of the Tons River (Uttarakhand). Journal of Mountain Research, 17(2), 97-107. https://doi.org/10.51220/jmr.v17i2.9
Smolar-Žvanut, N. and Klemenčič, A.K. 2013. The impact of altered flow regime on periphyton. Pp. 229-243. In: Maddock, I., Harby, A, Kemp, P. and Wood, P. (Eds.), Ecohydraulics: An Integrated Approach, Wiley Blackwell, Chichester https://doi.org/10.1002/9781118526576.ch13
Solak, C.N., Peszek, Ł., Yilmaz, E., Ergül, H.A., Kayal, M., Ekmekçi, F., Várbíró, G., Yüce, A.M., Canli, O., Binici, M.S. and Ács, É. 2020. Use of diatoms in monitoring the Sakarya river basin, Turkey. Water, 12(3), 703. https://doi.org/10.3390/w12030703
Steinberg, C. and Schiefele, S. 1988. Biological indication of trophy and pollution of running waters. Zeitschrift für Wasser- und Abwasser-Forschung , 21, 227-234.
Stevenson, R.J. and Bahls, L.L. 1999. Periphyton protocols. Pp. 6-22. In: Barbour, M.T., Gerritsen, J., Snyder, B.D. and Stribling, J.B. (Eds.), Rapid Bioassessment Protocols for Use in Wadeable Streams and Rivers: Periphyton, Benthic Macroinvertebrates, and Fish, 2nd ed., EPA 841-B-99–002. United States Environmental Protection Agency, Washington, D. C., USA.
Szczerba, A., Rzodkiewicz, M. and Tylmann, W. 2023. Modern diatom assemblages and their association with meteorological conditions in two lakes in northeastern Poland. Ecological Indicators, 147, 110028. https://doi.org/10.1016/j.ecolind.2023.110028
Tan, X., Zhang, Q., Burford, M.A., Sheldon, F. and Bunn, S. E. 2017. Benthic diatom-based indices for water quality assessment in two subtropical streams. Frontiers in Microbiology, 8, 601. https://doi.org/10.3389/fmicb.2017.00601
Toman, M.J., Grošelj, A.M. and Zelnik, I. 2014. The influence of selected factors on the distribution of epilithic diatoms in a torrential river the Kamniška Bistrica (Slovenia). Acta Botanica Croatica, 73(2), 447-463. https://doi.org/10.2478/botcro-2014-0004
ter Braak, C.F.J. and Smilauer, P. 2002. CANOCO Reference Manual and Cano Draw for Windows User’s Guide: Software for Community Ordination, (version 4.5). Microcomputer Power, Ithaca, New York, USA. 500 pages.
Tornés, E., Mor, J.R., Mandaric, L. and Sabater, S. 2018. Diatom responses to sewage inputs and hydrological alteration in Mediterranean streams. Environmental Pollution, 238, 369-378. https://doi.org/10.1016/j.envpol.2018.03.037
Trábert, Z., Duleba, M., Bíró, T., Dobosy, P., Földi, A., Hidas, A., Kiss, K.T., Óvári, M., Takács, A., Várbíró, G. and Záray, G. 2020. Effect of land use on the benthic diatom community of the Danube river in the region of Budapest. Water, 12(2), 479. https://doi.org/10.3390/w12020479
van Dam, H., Mertens, A. and Sinkeldam, J. 1994. A coded checklist and ecological indicator values of freshwater diatoms from the Netherlands. Netherland Journal of Aquatic Ecology, 28(1), 117-133. https://doi.org/10.1007/BF02334251
Virtanen, L. and Soininen, J. 2012. The roles of environment and space in shaping stream diatom communities. European Journal of Phycology, 47(2), 160-168. https://doi.org/10.1080/09670262.2012.682610
Virtanen, L.K. and Soininen, J. 2016. Temporal variation in community–environment relationships and stream classifications in benthic diatoms: Implications for bioassessment. Limnologica, 58, 11-19. https://doi.org/10.1016/j.limno. 2016.01.003
Wang, Y., Wu, N., Tang, T., Wang, Y. and Cai, Q. 2022. Small run-of-river hydropower dams and associated water regulation filter benthic diatom traits and affect functional diversity. Science of the Total Environment, 813, 152566. https://doi.org/10.1016/j.scitotenv.2021.152566
Wen, Y., Schoups, G. and van de Giesen, N. 2017. Organic pollution of rivers: Combined threats of urbanization, livestock farming and global climate change. Scientific Reports, 7(1), 43289. https://doi.org/10.1038/srep43289
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Tanuja Bartwal, Sandeep Kumar, Prakash Nautiyal
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
